Fuel/air mixing enhancement by cantilevered ramp injectors in hypersonic flows

摘要

An novel ramp injector design is presented for fuel delivery in high-enthalpy, high Mach number environments typical of those found in hypersonic propulsion systems such as the shock-induced combustion ramjet and scramjet. Advantages of the new cantilevered design exploit two main sources of vortex generation: baroclinic torque and cross-stream shear. The generation of vortices in a mixing environment serves to augment the inadequate process of shear layer mixing and diffusion needed in hypervelocity environments which entail short residence times. A baseline configuration of the cantilevered injector is solved numerically using a 3D, Navier-Stokes, TVD flow solver. Results are presented for an injector introducing hydrogen fuel into a high-enthalpy airstream and its performance as a mixing enhancer is assessed. Preliminary work reveals encouraging results for this new cantilevered design.